Apparatus for wrapper end closure



Dec. 1, 1959 H. RuMsEY, JR 2,914,898

APPARATUS FOR WRAPFEREND CLOSURE Filed May 28, 1956 2 Sheets-Sheet 1ATTORNEYS H. RUMSEY, JR

APPARATUS FOR WRAPFER END CLOSURE Dec. 1, 1.959

Filed May 2s, i956 2 Sheets-Sheet 2 INVENTOR ATTORNEYS United StatesPatent APPARATUS FOR WRAPPER END CLOSURE Herbert Rumsey, Jr., Rochester,N.Y., assignorto W. R. Grace & Co., Cambridge, Mass., a corporation ofConnecticut Application May 28, 1956, Serial No. 587,805

4 Claims. (Cl. 53-141) transparent sheet material around at least aportion of the package so that the food product is displayedtherethrough. Where this type of package is employed, the transparentwrapping material is often stretched tightly and made smooth so as topresent au attractive appearance and elect. Several types of wrappingmaterials can be shrunk by subjecting them to heat and these are oftenused in this industry. As an example, tensilized or oriented rubberhydrochloride, available commercially under the tradename Plioflm andtensilized or oriented polyvinylidene chloride, available commerciallyunder the trademark Saran can be used. When this type of wrappingmaterial is employed, it is wrapped rather looselyaround the package,the ends of the wrapper are closed and it is thereafter subjected to apredetermined temperature so as to cause it to shrink and therebytightly encompass lthe article wrapped therein while causing excess airwithin the package to be expelled through the overlapping seams of thefilm. Y

The invention is herein described with reference to shrinkable wrappingmaterial, however, it is obvious and should be borne in mind that thisapparatus and method can be employed for heat scalable films other thanthose which are heat shrinkable. n

The apparatus and method described herein provides a new means forlmwrapper end closure. In the past, the methods employed utilizedtwisted end closure means, but it has been found that certain items tobe packaged cannot be efliciently handled by the twisting equipmentbecause of their larger size, Weight, and odd shapes. An example of anitem in this category would be a smoked ham or a turkey weighing from 8to 24 pounds. invention provides an apparatus and method whereby theends of film wrappers so used are heat crimped rather than twisted forclosure.

The invention herein disclosed has, as its principal object, theprovision of an apparatus which permits the application of a high degreeof heat to the'end of a wrapping film at a predetermined area of thefilm. j

Another object of this invention is the provision of a Wrapper endclosure apparatus wherein the entry of the wrapper end to an operatingposition is controllable so as to avoid rupture of the wrapper.

Another object of the present invention is to provide a wrapper endclosure apparatus in which heat is applied under pressure. p

An object of this invention is to provide a means of applying adjustablesealing temperatures to a film and manual control of pressure at thesealing area to accommodate the heat sealing of a variety of films.

me ICC an apparatus for applying heat, to a wrapper lm which containsmeans for severing the film portion at a prede termined distance fromthe point of heat application simultaneously with the application of theheat.

The method and apparatus are described herein with reference to thedrawings in which:

Fig. l is a plan view of the apparatus with a wrapped I articlepositioned thereon;

Fig. 2 is a rear elevation view of the apparatus shown in Fig. 1illustrating the mechanical structure thereof;

Fig. 3 is a sectional view taken on the lines 3-3 of Fig. 2;

Fig. 4 is a partially sectional detailed view of the closure portion ofthe apparatus shown in Fig. 1;

Fig. 5 is a partially sectional top View of the heat closure jaws of theapparatus shown in Fig. l with a wrapper end inserted therein;

Fig. 6 illustrates a wrapped article after end closure and beforeshrinkage of the wrapper;

Fig. 7 shows the article shown in Fig. 6 after its wrapper has beenshrunk; and

Fig. 8 is a detailed View of an alternate form of jaw structure whichcan be used in the apparatus shown in Fig. l.

The apparatus used to practice my invention is illustrated in thefigures. In Fig. l, article 10 which is an article to be wrapped, isenclosed by wrapper 11. In order for wrapper 11 to completely enclosearticle 10 ends 11a and 11b of wrapper 11 must be closed. Wrapper 11 isa film of tensilized or oriented rubber hydrochloride,. orientedpolyvinylidene chloride or the like.

Article 10 is disposed upon platform 12 which lies at an angle with theVhorizontal. One end of platform 12 rests on an underlying surface andthe other end is supported by support member 13 whichis fastened toverltical member 14. Member 13 is a metal bar` which extends horizontalto the underlying surface and which is adjustable in a verticaldirection by means of screws 15. The height `of support member 13 abovethe underlying surface is determined by the size and `shape of thewrapped article and the method of determining this distance will be seenbelow. For the present, however, it should be recognized that platform12 enables an operator to easily position article 10 in the apparatus.vMem-` ber 13 and platform 12 are joined together by hinge means 13awhich allows platform 12 to assume an angle in accordance with thedistance bar 13 above the under lying surface.

Vertical member 14 together with base 16 form the mounting structure forthe mechanism which comprises my apparatus. Vertical member 14 and base16 can be formed from any sturdy material and are shown in the figuresas being mutually perpendicular, however, it vis not necessary that theylie at right angles to each other. Slot 17 is formed in the center ofVertical member 14 and extends vertically from its uppermost portion toa point approximately halfway up from base 16. Slot 17 is a V-shapedaperture having its broadened portion formed with rounded corners at theedge of member 14 asseen best in Fig. 2. i

Top plates 18 and 19 which are identical are pivotally connected tovertical member 14 at 2t) and 21 respectively. These plates present aflat shelf-like surface along the upper edge of vertical member 14andprovide arcuate ends 18a and 19a at the access to slot 17. The purposeand use f the top plates will be explained below and it will also beobserved that the plates are pivotal-ly mounted to A further object ofthis invention is the provision of j allow an operator to more easilyobtain access to the structure lying beneath them.

Considering Figs. 2 and 5, it is seen that heating blocks 22 and 23 aremounted at the rear of vertical` member 14 in the vicinity of slot 17.The heating blocks lie bepeath,

the top plates and each heating block has surfaces 22a and 23arespectively serving as a rearward extension of one Aside of the slot.Surfaces 22a and 23a are arcuate as seen best in Fig. 5. Plastic plates22 and 23' are at tached by screws to blocks 22 and 23 respectively.

Heating blocks 22 and 23 are rigidly attached by screws 24 to arms 25and 26 respectively which are each pivotally mounted at an end tovertical member 14 by bolts, bolt 27 serving as the pivotal connectionfor arm 2S and bolt 28 serving as the pivotal connection for arm 26. Y

Linking member 29 is pivotally connected at one of its ends to heatingblock 22 on the side of the block which is away from surface 22a. Theother end of linking member 29 is pivotally connected to member 30 whichis pivotally attached to base 16, by bolt 31 which is' maintained inposition by hinge 32.

Spring 33 yis attached to the top of heating block 22 at a point abovethe point whereat linking member 29 is pivotally connected to the block.The other end of spring 33 is attached to vertical member 14 at a pointabove member 30. Spring 33 maintains member 30 in a vertical directionby yieldingly urging it against stop 34 which is fastened to verticalmember 14. Linking member 29 is so constructed that when upright 30 isagainst stop 34, heat block 22 is held away from the center line of slot17.

Heating block 23 is mounted in exactly the same way as heating block 22.Linking member 35 is pivotally connected at one of its ends to heatingblock 23 on the side of the block which is away from surface 23a. Theother end of linking member 35 is pivotally connected to a member 36which is pivotally attached to baseV 16 by bolt 37 which is maintainedin position by hinge 38.

Spring 39 is attached to the top of heating block 23 at a point abovethe point whereat linking member 35 is pivotally connected to the block.The other end of spring 39 is attached to vertical member 14 at a pointabove member 36. Spring 39 maintains member 36 in a vertical directionby yieldingly urging block '23 away from the center line of slot 17.

Lever 40 is rigidly connected to the lower portion of member 36. Lever40 and member 36 are connected in such a way that when member 36 isvertical lever 40 makes an angle of approximately 30 with thehorizontal. Likewise, lever 41 is rigidly connected to the lower portionof member 30 in such a way that when member 30 is vertical, lever 41makes an angle of approximately 30 with the horizontal. As seen in Fig.2 lever 41 extends upwardly at an angle with its uppermost portion inthe vicinity of top plate 19. Shelf member 42 is rigidly attached to theupper end of lever 41 in such a way that shelf member 42 liesperpendicular to vertical member 14. Lever 40 extends upwardly at anangle to a point whereat its uppermost end lies slightly beneath thesurface of shelf member 42. Bar 43 which `is mounted on lever 40 tat itsend serves to maintain the endof lever 40 adjacent lever 41, since theupper end of lever 41 lies between bar 43 and lever 40 and the bottomedge of lever 41 rests on circular member 43' which is mounted betweenlever 40 and bar 43. Spring 39 therefore cannot draw member 23 away fromslot 17 since member 30 lies against stop 34.

As will be seen below, when the operation of the device is considered,the construction of levers 41 and 40 is such that upon clockwiserotation of lever 41 as seen in Fig. 2 lever 40 will be rotatedcounterclockwise since the lower edge of lever 41 bears against circularmember 43' and bar 43 will maintain lever 40 in sliding positionadjacent lever 41. f

Conductor 44 connects rheostat 45 to any conventional source ofelectrical power such as 115 volts 60 cycle'A.C. voltage. Rheostat 45can be any conventional type rheostat having a control 46 by means ofwhich the ow of electrical power therethrough can be regulated. Lead 47connects heating element 48 to the power source through rheostat 45 andconductor 49 connects heating element 50 to the source of electricalpower through rheostat 45. Thus, the temperature of heating elements 48and 50 is regulated by rheostat 45.

The manner of sealing the lm at the ends of a package with my apparatuswill be now considered. Power is supplied to rheostat 45 and control 46is operated so that the heating elements heat their respective heatingblocks to a temperature slightly higher than the melting point of film11. Article 10 is positioned on platform 12 in such manner that end 11bis adjacent slot 17. An operator then grasps end 11b with one hand asshown in Fig. 5 and places the fingers of his other hand on end 11badjacent article 19. End 11b is then placed in 17 as shown in Fig. 5 andas this end is brought in contact with shelf 42, levers 41 and 40operate to bring heating blocks 2T. and 23 in contact with envelopes11b, thus heat sealing areas of `the film a predetermined distance fromarticle 10.

Since both hands of the operator will usually be used to place the endof the wrapper between the jaws of the apparatus, one hand will bebetween the heat crimped area and the body of the wrapped article. Thismeans that the heat crimped area can be maintained at a predetermineddistance such as 2 or 3 inches from the end portion of the wrappedarticle.

Knife edge 51 as seen in Fig. 5 severs the extreme end of envelope 11bcleanly. Lever 41 is released as the operator removes his hand from itso that heating blocks 22 and 23 will return to their original positionswithout applying such excessive heat to envelope 11 that it meltsthrough at the points of contact of heating blocks 22 and 23 with thisenvelope.

Plastic plates 22' and 23 serve as an auxiliary crimping means andaccomplish a slight degree of heat sealing at the points at which theycome in contact with envelope 11 since the heat of blocks 22 and 23 istransferred to these plates by means of conduction. The temperature ofthe plastic plates due to their composition, however, is always lowerthan the metal and never sufficiently hot to melt through the film.

It should be understood that this operation can be accomplished almostequally well without the use of knife edge 51.

After end .11b has been heat crimped, end 11a is also heat crimped inthe same manner and the wrapped article appears as shown in Fig. 6.Thus, heat sealing end lm closure has been accomplished at a distancespaced from the end of the product packaged. If the wrapper is to beshrunk the article is then subjected to heat as by being submerged inwater heated to from to 210 Fahrenheit and the envelope 11 shrinks sothat a taut package such as that shown in Fig. 7 will result sinceexcess air within the package has been expelled through the overlappingseams of the lm or punched holes in the wrapper if it is so desired.

The relative positions of the heat crimped or heat sealed areas 11a and11b prior to heat shrinking is shown in Fig. 6' with the sealed areasspaced from the ends of the wrapped article. Fig. 7 shows the packageafter heat shrinking with the wrapper stretched tightly around thepackaged article and with the heat sealed areas disposed immediatelyadjacent the article.

Fig. 8 illustrates another form of heating block. In Fig. 8, heatingblock 52 with heating element 53 therein and heating block S4 withheating element 55 therein are used rather than the heating blocksaforedescribed. It is to be noted that heating block 54 has thereon atthe surface adjacent the envelope a contact point 56 while heating block52 has at the edge of it which is adjacent the envelope contact point57. In Fig. 8 Contact point 57 is spaced away from the adjacent heatingblock 54 and contact point 56 is in direct contact with its adjacentheating block 52. This assembly provides a lesser degree of pressure at57, thus minimizing a melt through and providing a crimp only whereas acompleted contact at 56 under pressure serves as a severing means at thesame time the heat sealing function is performed. Thus, it isunnecessary with the embodiment shown in Fig. 8 for a cutting blade tobe provided.

It is seen in Fig. 4 that Teflon strip 58 is attached at one of its endsto heating block 22 and at its other end to heating block 23. Weight 59maintains the center portion of strip 58 below slot 17 so that the Teonstrip covers surfaces 22a and 23a of heating blocks 22 and 23respectively. This Teflon strip allows for a more even distribution ofheat when the heating blocks are applied to an envelope. This feature isoptional and its use is dependent on the type of film being used, degreeof heat required, and the speed at which it is desired the unit operate.

It should also be noted that even though slight amounts of air may betrapped inside the package after it has been heat treated the constantpressure exerted by the shrunk lm will eventually force this air outthrough the seams of the package or through voids deliberately createdfor air expulsion.

Thus, among others, the several objects in the invention as specificallyaforenoted are achieved. Obviously, numerous changes in construction andarrangement of the parts might be resorted to without departing from thespirit of the invention as defined by the claims.

I claim:

l. An apparatus for applying heat to an end of an `article wrapperincluding in combination a mounting, a

heating block pivotally connected to said mounting, a second heatingblock also pivotally connected to said mounting, means to heat saidheating blocks, guide means formed in said mounting, spring meansyieldingly y urging said rst heating block away from said guide means,second spring means yieldingly urging said second heating block awayfrom said guide means, stop means capable of limiting the distance saidrst block can travel away from said guide means, second stop meanscapable of limiting the distance said second block can travel away fromsaid guide means, lever means connected to said first block whereby saidblock can be pivoted toward said guide means, and second lever meansconnected to said second block whereby said second block can be pivotedtoward said guide means, said first and second lever means beingoperatively interconnected so that when said rst lever means is operatedsaid second lever means is also operated and said first and secondheating blocks are brought together and in contact with the end of saidarticle wrapper which is disposed in said guide means.

2. Apparatus for applying heat to the projecting end of an articlewrapper as set forth in claim 1 in which a strip of flexible material issecured to the first and second heating blocks and extends downwardlyover the confronting faces thereof forming a bight and a weight ispositioned in the bight portion of the strip to maintain the strip inrelatively taut condition.

3. An apparatus for applying heat to an end of an article wrapperincluding in combination a mounting, a heating block pivotally connectedto said mounting, a

second heating block also pivotally connected to said mounting, saidfirst and secondheating blocks being in spaced relation with oneanother, a surface on said first heating block opposite said secondheating block, a second surface on said second heating block oppositesaid rst surface, means to heat said heating blocks, guide Ameans formedin said mounting, spring means yieldingly urging said rst heating blockaway from said guide means, second spring means yieldingly urging saidsecond heating block away from said guide means, stop means capable oflimiting the distance said rst block can travel away from said guidemeans, second stop means capable of limiting the distance said secondblock can travel away from said guide means, a lever pivotally mountedon said mounting, linking means connecting said lever to said rstheating block, a second lever pivotally mounted on said mounting, secondlinking means connecting said second lever to said second heating block,

and connecting means mounted on said second lever whereby said secondlever is operatively connected with said irst lever so that when saidfirst lever is operated,

said second lever is also operated and said rst and second surfaces arebrought together and in contact with the end of said article wrapperwhich is disposed in said guide means.

4. Apparatus for use in heat sealing the projecting end of a packagewrapper comprising: a vertically disposed member having a V-shaped guideopening extending downwardly from its upper surface and serving as aguide -for the projecting wrapper end; a relatively flat angularlydisposed platform for holding the package disposed be- `neath the guideopening so that the projecting package `end may be inserted therein,said platform having connection with said vertically disposed member forrelative vertical adjustment; a pair of pressure blocks having heatingmeans shiftably mounted on said vertically disposed member adjacent saidV-shaped opening; and means operatively connected to said blocks forshifting them towards each other so that a projecting end of a packagewrapper disposed in said guide opening will be engaged and heat sealedby said blocks.

References Cited in the le of this patent UNITED STATES PATENTS1,875,979 Beutel Mar. 1, 1932 1,964,020 Alm et al June 26, 19342,071,300 Gammeter Feb. 16, 1937 2,103,945 Henley Dec. 28, 19372,248,248 Nye July 8, 1941 2,340,510 Corley Feb. 1, 1944 2,480,082 LowryAug. 23, 1949 2,638,963 Frederick et al May 19, 1953 2,656,657 BartleOct.- 27, 1953 A OTHER REFERENCES Modern Packaging, April 1956, pages122-126.

